Apparatus for removing sludge from sewage tanks and the like



March 25,1941;- 4 S.`B.P LE l 2,236,128-

- APPARATUS FOR REMOVING SLUDYGV: FROMSEIWAGEA TANKS AND THE LIKE Filedsept. 14, 1938 4 sheets-sheet 1 l O I z,

I Il 1 i; yl.-

March 25, 1941. s. B. PooLE APPARATUS FOR REMOVING .SLUDGE FROM SEWAGETANKS AND THE'LIKE Filed sept. 14, 193e 4 sheets-sheet 2 March 25,1941.` s, BfpvoLE 2,236,128

, APARA-'rus FOR REMQVING 'sLUDGE FRSOM SEWAGE 'mms AND THE:v LIKE i'Filed sept. 14, 193s 4 sheets-sneu s March 25; 1941 s. BQPooLE A.2236.128

APPARATUS FOR REMOVING SLUDGE FROM SEWAGE TANKS AND THE LIV-KE FiledSept. 14, 1938 4 Sheets-Sheet 4 liz',

' Inv/anion J7WM3SW.

A Jaarw Patented Mar. 25, 1941 PATENT OFFICE APPARATUS FOR,REMOVINGSLUDGE FROM SEWAGE TANKS AND THELIKE f Sydney Bennett Poole;Radcliie,` near Manchester, Englandl ApplicationSeptember 14, 1938,Serial No. 229,920 In Great Britain February 28, 1938- Claims.

This invention relates to that kind of appara tus for remo-ving sludgefrom sewage tanksand the like wherein means are caused to travel abovethe bottom of the tank and sludge is discharged 5 through the said meansby hydrostatic head.

Hitherto the said means comprised a single perforated pipe extendingacross or `half way across the tank and discharging from a single outletsituated at the requisite distance below the normal liquid level in thetank.

The object of my invention is lto. provide a novel form of apparatus ofthe said kind which amongst other advantages enables the sludge tobe-removed uniformly from 'all parts of the :sew age tank or the like insuch .amanner that there is no undesired accumulation in some` partswhilst only liquid is beingfdrawn from other parts.

An apparatus of the' hereinbefore specified kind for removing sludge'from sewage tanks and the likein accordance with my invention comprisesa plurality of nozzles each of which sweeps a different portion of the.bottom of the sewage tank or the like and has a separate dischargepassage delivering sludge over a separate sludge Weir situated below thenormal liquid level into av passage the bottom of which is also situatedbelow the said liquid level.

The sludge received by the passage may be discharged either by gravityor a syphon or power.

The said weirs are preferably'arranged adjustable whereby thehydrostatic head can be varied separately for each nozzle.

The said nozzles may be providedwithcir'- cular inlet apertures but Iprefer to pro-vide them with one or more inlet slots which may or maynot be arranged adjustable in size. I

The said nozzles may be connected to theweirs by upwardly projectingpipes adapted. to be swung jointly or singly and with or without thesaid passage into a position above the normal liquid level or above thetopl of the sewagetank or the like to enable the nozzles to be easily 45cleaned without emptyingthe sewage tank or the like; and/or to enablethe sludge collecting apparatus to be moved from' one sewage tank or thelike to another.

The said passage, which travels with the noz-A zles, may be providedwith a de-scumrning'weir adapted to be closed or votherwise renderedinoperative when not required;

Access to thesludge -weir's-is preferably-provided, y f' The.saidzaccess mayfbe arrangedA forbyf pro-i vidingthe said .passage withan open top situated above water level and through which the sludgeweirs vare-accessibleandvisible, the said open top being provided or notwith a removable .r

cover or covers.

An important advantage of the hereinbefore described: form of apparatusis that it enables all-conduits to be so arranged that they can have a.cleaning implement pushed into them for cleaning purposes. 10

I-attain the hereinbefore stated object `by the means illustratedintheaccompanying drawings;4 whereinsy Figure 1 is 2a.front view, partlyAin-section of l an apparatus for .removingsludge from a sewage tank. v

Figure 2V is a-plany .view thereof.

Figure isan'end view-in section thereof.

Figure 4 is a-fragmentaryfront view partly in Y section, .of a-portionof an apparatus for remov- 5 ingsludgefrom'a sewage tank and illustratesanother construction.

Figurer 5 isa fragmentary-end view insection thereof.

Figure-6 is a fragmentary plan view thereof.

Referring1 to the drawings, in the construction shown in Figure l, asapplied by way of .example to a circular'sewage tank I or the like, Iprovide a-travelling-gantry2 one end of which is ror. tatably mountedV'ona-central' pillar 3 provided in 30 the sewage .tank-.I or the likeandthe other end of which ltravels on air circular track 4 around thesewage tank' I or theflike, thegantry 2 thus extending halfway acrossthe sewage tank I o-r Y. the likeand rotating above-the same. 35

' Thefgantryv Zcarriesa trough 5. which is radial` to the. sewage tanklI or the like and extends from .theperiphery.. to near the centrethereof. The bottom of the trough 5 is stuated below normal Awater leveland the top is situated. above the same. In thetrough there areprojecting upwardly from a step 6 in the saidbottom a longitudinal rowof bell-mouthed vertical j pipes 'Vthe enlargedorifices of which lconstitute horizontal circular sludge weirs. The pipes v'I arevertically adjustable. separately to enable the' heights of the orificesYto be independently adjustable; for example .by screwing them into andout'of'bosses 8 secured to the trough-5. The pipes 'I communicate withaper- 50 tures in the step 6, and beneath the trough 5 therleareall-corresponding number of depending elbow pipes '19 secured to' the`underside Y of :the trough .5 andeachf communicating-with one 4ofpending elbow pipe I8 swvellably connected at its upper end to its lowerelbowed end. Each of the elbow pipes I0 has secured to its lower end ahorizontal nozzle pipe II having an inlet slot I2 extending along itsunderside in a position where it can receive the sludge lying on thefloor of the sewage tank I or the like. Each of the nozzle pipes II hasno communication with the others, but all the said nozzle pipes may beconnected together mechanically end to end in alignment with each other.The nozzle pipes II each sweep a different part of the said oor, butthey jointly sweep the whole of the said floor. The nozzle pipes areconnected together for example by the aid of iianges I3 provided on theopen ends thereof, a blank plate I4 being provided between each twoadjacent ends to close them from each other.

A pipe I5 is connected to the inner end of the trough 5 to empty thetrough 5 continuously by a syphon action or, as shown, by gravity. 'Ihepipe I5 may extend down a central hole I6 in the said pillar. A squeegeeI1 may be hinged to each nozzle pipe II to assist the action of thenozzle pipes Il. l

In use the nozzle pipes II are caused by the travelling gantry 2 totravel circularly and sweep the whole of the floor of the sewage tank Ior the like. The sludge in which the slots I2 are immersed is caused bythe hydrostatic pressure of the head of liquid above it to enter thenozzle pipe II and flow up through the elbow pipes I0 and 9 and the weirpipes 1, and over the sludge weirs into the trough 5. The sludge thenlows along to the inner end of the trough 5 where it is dischargedthrough the pipe I5.

The rate of iiow of sludge through each nozzle `-pipe II is dependent onthe distance at which the sludge weir of the weir pipe 1 serving thesaid pipe II is situated below water level. Therefore by arranging oradjusting the Weir pipes 1 so that the sludge weirs are at diierentdistances below the said level, the rate of flow from one nozzle pipe IIcan be made different from those of the other nozzle pipes II. Thereforethe rate `of removal of sludge from one portion of the sewage tank I orthe like can be made greater or less than that at another portion sothat no por# tion shall become free of sludge before another.Furthermore if liquid enters the apparatus, it can interfere with thesludge removing action of one 'nozzle pipe II only and not of the wholeapparatus. The trough 5 is vertically above the nozzle pipes I I and theconnections between the lnozzle pipes II and trough 5 are consequentlyof minimum length. Therefore a minimum of resistance to the hydrostaticpressure is obtained and the danger of blockage is reduced. Furthermorea iiexible cleaning rod o r wire can be readily pushed through each ofthe bell mouthed weir pipes I and the elbow pipes 9 and I0 down to thenozzle pipe II at any time without dismantling any of the parts. Thenozzle pipes II can also be raised by swivelling the elbow-pipes I0 onthe elbow pipes 9, for example through the medium of a device comprisingworms I8 and segments I9 and operated from the travelling gantry forexample through shafts 20, pairs of gear wheels 2|, a shaft 22, a pairof gear wheels 23, a pair of sprocket wheels connected by a drivingchain 24 and a crank handle 25. When the nozzle pipes II are raised,their slots I2 can-be cleaned with a brush or scraper wielded from the.travelling gantry 2. It is thus a simple matter-to ensure and maintainan efiicient action ofthe apparatus- If desirable the slots I2 may bearranged adjustable, for example by providing one side of the slot I2 ona hinged flap forming part of the nozzle pipe Il so that the width ofthe slot can be increased or diminished by turning the iiap on itshinge. A rod pivotally connected to the flap and extending upwards tothe travelling gantry 2 may be provided to turn the iiap and if desiredto also hold it in any position of adjustment.

A scum decanting penstock 2B is preferably provided at one side of thetrough 5, whereby, when required, scum which oats on the liquid can bedecanted into the trough 5 and be discharged therefrom in the samemanner as the sludge. The penstock 26 is movable as usual into and outof operative position by means of a hand wheel 21.

The top of the trough 5 may be provided with removable covers.

A similar construction to that hereinbeiore described can be employedfor removing sludge from rectangular sewage tanks and the like, the

travelling gantry 2 and trough 5 being however arranged to extent acrossand travel along the tank and the series of nozzle pipes Il beingarranged to extend across and sweep the width of the rectangular sewagetank or the like. The sludge from the trough 5 is discharged by a syphonor by power into a longitudinal channel provided at one side of thesewage tank or the like. In this construction, instead of arranging thenozzle pipes I I only to be swung up, both the trough 5 and the nozzlepipes I I may be arranged to be swung up together so that they can beraised clear of top of the sewage tank or the like in order to enablethe travelling gantry to travel to and the nozzle pipes I I to belowered into and ulsied in one or more further sewage tanks or the li e.

In the construction illustrated in Figures 4 to 6 each nozzle piece 28has an interior which, regarded in end sectional View, see Figure 5,widens from the nozzle orifice upwards, but regarded in front sectionalview, see Figure 4, narrows into two passages 29 and 3D which join againat 3I whereby a more uniform suction along the length of the nozzleorifice is attained. Each nozzle piece 28 is mechanically separate fromthe others and is hinged at 32 to a vertical pipe 33 having a flange 34forming a seat for a ilange 35. Rods 36 are connected to the ange 35 andproject through clearance holes in the ange 34. Above the flange 34,helical compression springs 31 are provided on the rods. The upper endsof the compression springs 31 are held against axial movement on therods 36 and the lower ends of the said springs rest on the flange 34.Each nozzle pipe 28 is thus free to swing automatically on its pivot 32lagainst the action of the springs 31 on encountering an obstacle andreturns to its operative position when it has ridden over the obstacle,whereby damage to the apparatus by solidpobjects in the sewage tank orthe like is avoided. The springs 31 ensure a tight joint between'thenozzle pipe 28 and the pipe 33 under normal conditions.

'I'he pipe 33 is secured to an external lug 38 provided laterally onv asubstantially V-sectioned trough40 with roundedfloor 39. The lug 38 ishollow and its interior communicates with the interior of the trough 40.The lug 38 has an aperture, and a Weir pipe 4I extends through the lug38 and aperture therein and is screwed into the-A upper, enlargedv endof the pipe 33. The

Weir pipe has a bell-shaped upper end the rim of which forms thecircular Weir.

The pipe is steadied by a steady rod 42 suitably secured to the gantry43.

It will be appreciated that if desired nozzle pipes similar tothe nozzlepipes 28 may be employed in place of the nozzle pipes I I either with orwithout the hereinbefore described provision for automatic yielding ofthe nozzle pipe on meeting a solid obstruction. If such provision ismade, a lifting mechanism such as that comprising the worm I8 andsegment I9 is provided to turn each of the pipes I0 in an upwarddirection when required for cleaning and so forth. All of these wormsmay be driven jointly or separately. When driven separately, individualnozzle pipes can be raised independently of the others for cleaning orinspection.

A scum decanting penstock 43 may be provided on the trough 40. Eachnozzle pipe 28 may be provided with a squeegee 44.

1. An apparatus for removing sludge from a sewage and the like tank,comprising in combination, means for producing a normal liquid level inthe tank, a gantry above the tank, means for supporting the gantry abovethe tank, means for traversing the gantry over the tank. a sludgeconduit supported by the gantry with the lower part of the conduit belowand the upper part thereof above the normal level of liquid in the tank,an outlet pipe connected to the conduit, a plurality of sludge pipesconnected to the conduit with their open tops situated below the saidnormal level and forming sludge weirs, and a. plurality of elongatednozzles provided on the sludge pipes in alignment with each other forsweeping the bottom of the tank.

2. An apparatus for removing sludge from a circular sewage and the liketank, comprising in combination, means for producing a normal liquidlevel in the tank, a gantry above the tank and extending from theperiphery tothe centre thereof, means for supDOrting the gantry abovethe tank, means for rotating the gantry over the tank, a sludge conduitsupported by the gantry with its upper portion situated above the normalliquid level in the tank and its lower portion situated below the saidlevel, a sludge outlet pipe connected to the conduit at that end whichis nearest the centre of the tank for discharging the sludge centrallyof the tank, a plurality of sludge inlet pipes connected to the sludgeconduit and terminating near the bottom of the tank, weirs arranged inthe conduit at a level below the normal liquid level for controllingseparately the inlet of sludge from the inlet pipes into the sludgeconduit, means for adjusting the said weirs, and elongated nozzlesconnected to the inlet pipes in alignment with and abutting against oneanother for sweeping over and thereby drawing sludge directly from thewhole surface of the bot-- tom of the tank.

3. An apparatus for removing sludge from a sewage and the like tank,comprising in combination, means for producing a, normal liquid level inthe tank, a plurality of nozzles, a travelling gantry, means forsupporting the gantry above the tank, means for driving the gantry, aconduit supported by the gantry with the upper part of the conduit aboveand the lower part below the normal sewage level in the tank, aplurality of upwardly projecting pipes connected separately to the saidnozzles and to the said conduit, and a weir arranged below normal liquidlevel and provided at the upper end of each of the said pipes fordischarging sludge therefrom into the conduit.

4. An apparatus according to claim 1, comprising means for permittingtilting of each nozzle separately on encountering an obstruction to itsnormal movement and means for automatically returning each nozzleseparately to its initial position after it has passed over theobstruction.

5. An apparatus according to claim 1, comprising hinge means connectingeach nozzle to its sludge pipe for permitting the nozzle to tiltupwardly to the rear on meeting an obstruction, and compression springoperating between each nozzle and its sludge pipe for returning thenozzle to its initial position after tilting.

SYDNEY BENNETT POOLE.

